The present invention relates to the use of nitrated fatty acids as therapeutics for treating type-2 diabetes. Fatty acids are both physiological energy sources and mediators of signaling events involved, for example, in inflammation and in energy homeostasis.
Saturated, unsaturated, and polyunsaturated fatty acids have been identified to date. Unsaturated electrophilic fatty acids have emerged as an important class of endogenous signaling molecules. Within this class are fatty acid hydroperoxides, keto fatty acids, and nitrated fatty acids, among others. For example, see Freeman et al., Chem. Res. Toxicol. 12:83-92 (1999), and Lima et al., Biochemistry 41:10717-22 (2002).
The signaling ability of nitro fatty acids stems predominantly from their ability to form reversible covalent adducts with nucleophilic centers of cellular proteins that are implicated in various transcriptional and cellular signaling processes. In particular, regulation of signaling activity most often occurs via the covalent modification of an active site thiol group of a protein target.
Recent studies suggest that nitro fatty acids such as 9- or 10-nitro octadecenoic acid (“nitro oleic acid”) and the various regioisomers (9-, 10-, 12- and 13-nitro) of nitro linoleic acid are adaptive mediators that play a crucial role in linking disease processes with underlying cellular events. See Freeman et al., Proc. Nat'l Acad. Sci. USA 99: 15941-46 (2002). In particular, nitro fatty acids modulate the activity of the peroxisome proliferator activating receptor gamma (PPAR-γ), for example, in response to inflammation and metabolic imbalance.
While both nitro oleic acid and nitro linoleic acid interact with PPAR-γ, little is known about the structural and biochemical determinants that account for their PPAR-γ activity and the related downstream activation of gene transcription. Consequently, no systematic approach exits for the design of pharmacophores that can modulate PPAR-γ activity.